Mutagenic Effect of Gamma Radiations on Forage Yield of Egyptian Clover (Trifolium alexandrinum L.)

The objective of the present study was to evaluate the effectiveness of different gamma-ray doses (0, 15, 30, and 45 Kr) during M1 and M2 generations on four multi-cut cultivars of Egyptian clover, or berseem (Trifolium alexandrinum L.), namely Hatuor, Narmar, Helaly, and Khadrawy. The M1 generation showed significant differences in plant height and tillering capacity at the second cut due to gamma doses. In contrast, the M2 generation showed highly significant differences in plant height at the fourth cut. Moreover, in the M1 populations, the Helali cultivar produced the tallest plants (87.6 cm) at a dose of 15 Kr, followed by the Khadrawy cultivar (87.1 cm) at a dose of 45 Kr. In the M2 generation, the Khadrawy cultivar recorded the highest plant height (85.1) at 30 Kr followed by Hatour cultivar (82.4 cm) at 15 Kr of gamma ray at the first cut. The results also indicated no significant differences between gamma-ray doses over all cultivars on fresh and dry yield at each cut and total cuts in both M1 and M2 populations. However, significant interaction effects were recorded between cultivar and gamma radiation dosage on such traits in the M1 generation. The estimates of high heritability in a broad sense coupled with high genetic advance as a percent of mean were observed for total fresh yield at 45 Kr and 30 Kr in M1 and M2 generations, respectively.